FDA Approves Therapy for Adults With Chronic Inflammatory Demyelinating Polyneuropathy

Officials with the FDA have approved the supplemental Biologics License Application for Pfizer’s immune globulin intravenous [human] — ifas (Panzyga) 10% liquid preparation for treatment of a chronic inflammatory demyelinating polyneuropathy (CIDP) in adults. According to Pfizer, this drug is the only intravenous immunoglobulin (IVIg) with 2 FDA-approved maintenance dosing options for CIDP, a rare neurological disease of the peripheral nerves, and can be administered at infusion rates up to 12 mg/kg/min.

“Each patient with CIDP has different treatment needs, and we have found that having 1 approved dosing option is not always optimal,” said Angela Lukin, global president, Hospital Business Unit, Pfizer Inc., in a prepared statement “The approval of this new indication with additional dosing options helps address an unmet patient need by providing healthcare providers with the ability to choose an approved dose that's right for patients.”

CIDP is characterized by gradually increasing symmetrical motor and sensory loss and weakness associated with loss of deep tendon reflexes. It is caused by damage to the covering of the nerves, called myelin. The gradual onset of CIDP can delay diagnosis by several months or even years, resulting in significant nerve damage that may limit and delay the response to therapy. Most individuals will require long term treatment, and nearly a third of patients with CIDP will progress to wheelchair dependence if left untreated. Early recognition and proper treatment are critical in helping patients avoid a significant amount of disability.

The approval for this new indication was based on data from a prospective, double-blind, randomized, multi-center phase 3 study in 142 patients diagnosed with CIDP. This study was the first IVIg CIDP treatment study to evaluate more than one maintenance dosing option. Efficacy, safety, and tolerability was observed during 7 maintenance infusions at 3-week intervals over a 6-month period. The primary efficacy endpoint was the proportion of responders in the 1.0 g/kg immune globulin intravenous [human] — ifas treatment arm at 6 months relative to baseline. A responder was defined as a patient with a decrease of at least one point in the adjusted 10-point Inflammatory Neuropathy Cause and Treatment (INCAT) disability score. The primary endpoint was met with 80% of patients in the study achieving an INCAT response with the 1.0 g/kg dose. Dose-dependent efficacy was shown by several supporting endpoints, including a 92% response in adjusted INCAT score in the 2.0 g/kg dose arm. Dose-dependent responses were also demonstrated in the 1.0 g/kg and 2.0 g/kg dose arms in grip strength, Inflammatory Rasch-built Overall Disability Scale (I-RODS) and Medical Research Council (MRC) sum scores. The immune globulin intravenous [human] – ifas treatments were generally well tolerated.

The most common adverse reactions (>5%) across all dosing arms were headache (15%), fever (14%), dermatitis (10%), and blood pressure increase (8%). During the study 11 patients (8%) received premedication.

Pfizer’s immune globulin intravenous [human] — ifas was previously approved by the FDA for the treatment of primary immunodeficiency in patients age 2 years and older and for chronic immune thrombocytopenia in adults.

REFERENCE

U.S. FDA Approves PANZYGA for the Treatment of Adults with Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) [news release]. New York, NY; February 12, 2021: Pfizer. Accessed February 15, 2021. https://www.pfizer.com/news/press-release/press-release-detail/us-fda-approves-panzygar-treatment-adults-chronic